[SpicyLemonZest]

The market didn't always work that way. Until Google monopolized it, search engines and ad networks were independent pieces competing on an open market. For example, one of early Google's successes was getting Yahoo to license its search engine.

[adventured]

> Until Google monopolized it, search engines and ad networks were independent pieces competing on an open market

It was always a mixture of both scenarios.

Yahoo prior to using AltaVista, Inktomi or Google had its own search tech - going back to 1995 - and its own advertising network.

AltaVista had its own search tech and its own ad network.

Lycos, a top 5 portal at the time, had its own search tech and its own ad network.

GoTo.com, very popular in its day, was both a search engine (acquired) paired up with its own famous ad system.

For several years AOL flirted on & off again with their own search tech, initially based on WebCrawler, prior to and after their deal with Excite. They also ran their own ad network.

[klipt]

Google tried monetising search in other ways and apart from ads, none of them would have kept the company profitable. Even duckduckgo which considers itself the "anti Google" gets all its money from ads.

[lonelappde]

That's not a response to parent comment, which is about competitiveness in the ad placement market, not ads on Google Search.